Modeling materials have been known and used since ancient times. Water-based clays which were found to be capable of being molded were either sun-dried or, later, kiln-fired in the manufacture of pottery and for sculpting of objects of both practical and aesthetic value. In order to overcome some of the problems with water-based clays, other clays were formulated, the best known of which are the composition clays of the Plasticine type. These clays consist of an earth-clay, an inert filler, and varied petroleum derivatives or oils employed as plasticizers. However, these Plasticine type clays tend to remain permanently soft.
All of these known clays and waxes, which have been used by artisans and sculptors for a long period of time, have significant drawbacks which must be overcome by the artisan or sculptor in order to achieve satisfactory results when used for modeling. Since the clays tend to crumble or to sag if drawn out to fine sections, sculptors in particular find the lack of the ability to provide fine detail in the clay and its lack of responsiveness a source of continuing frustration. In order to overcome the tendency of the clay to sag, the sculptor must devise mechanical interior bracing or armatures to provide the necessary support for the model and the weight of the clay itself becomes prohibitive in large models. Further, the fact that clay does not even come close to the look of a subsequent casting in metal means that the sculptor cannot easily communicate his vision of the final casting to those people most involved in the desired result, that is, the persons commissioning the object.